1）adj.兩者
一般單獨(dú)修飾名詞（復(fù)數(shù)）做前置定語（但名詞前不能有其他限定詞修飾）,不做表語/補(bǔ)足語.
如：There are many flowers on both sides of the street.
2）pron.兩者
可以單獨(dú)使用（相當(dāng)于名詞）,也可以構(gòu)成“both of + 其他限定詞 + 名詞（復(fù)數(shù)）”或“both of + 代詞”結(jié)構(gòu).
Both are my good friends.
Both of the boys over there are my good friends.
Both of them are my good friends.
3）adv.兩者都
一般放在句中,即be動詞之后/前均可,助動詞/情態(tài)動詞/行為動詞之前.
They are both my classmates.
They both can play soccer well.
They both have a good son.
4）conj.不僅...而且...；...和...都...
一般構(gòu)成both...and...結(jié)構(gòu),用于連接句中任意兩個并列部分.
如果并列兩個主語,謂語動詞一般采用復(fù)數(shù)形式.
如：Both you and I are students.
I can speak both English and Chinese.
They can both sing and dance.
The boy is so lazy that he sleeps both in the daytime and at night.